Electric fuse



T. E. IVIURRAY.'

ELECTRIC FUSE.

APPMCATION FILED OCT-12, 1918- 1,339,965. Patented May 11,1920.

UNITED sTATEs PATENT OFFICE.

THOMAS E. MURRAY, NEW YORK, N. Y

ELECTRIC FUSE.

Specification of Letters Patent.

Patented May 11, 1920.

Application filed October 12. 1918. Serial No. 257,844.

' To all whom. it may concern:

Be it known that I, THOMAS E. MURRAY,

a citizen of'the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Electric Fuses, of which the following is a specificalongitudinal section of the fuse case.

venting any possible short-circuiting of the fuse, as may'happen when the casing 'is closed :or covered at its ends by metallic Similar numbers of reference indicate like parts.

The fuse case comprises a hollow tubular body portion 1, having at its ends inturned flanges 2. The extremities of the body portion 1 are closed by plaster of Paris plugs 3, 4, in which the flanges 2 are embedded. Metal rods 5, 6,.which form the fuse terminals, are embedded in the end plugs 3, 4. Between said terminals extends the fuse strip 7, passing through the plugs 3, 4 and through a mass 8 of comminuted refractory material, such as dry plaster, which fills the space within the tubular body portion 1 and between the plugs 3, 4. If desired, the tubular body portion 1 may be provided with a paper lining 9.

Instead of making flanges 2 at the ends of the tubular body portion 1, I may form struck up projections 10 on the inner side of said body portion near the extremities thereof, which projections engage with the plasterof Paris plugs.

It is to be especially noted that the joints between fuse strip and terminal rods are completely embedded in the plaster end plugs, and so protected; also that the plugs extend beyond the extremities of the easing, thus guarding said extremities and pre capszvtha't the casingand plugs are united simply by inwakrdlyturned projections on the vcasing, such as-the flanges 2 or'struck upprojections 10, andalso that the casing ends register in outside diameter with the shoulders on the plugs, so that the exterior of the fuse presents a smooth finish. In making the fuse case the plaster forming the plugs is inserted in a soft or plastic state and the flanges are embedded therein, so that when the plaster sets they are firmly held.

I claim:

1. An electric fuse, comprising 'a tubular casing, a fuse strip therein, terminal rods connected to the ends of said strip, and two bodies of insulating material completely em bedding the joints between said rods and said strip and closing the ends of said cas- 2. An electric fuse, comprising a tubular casing, a fuse strip therein, terminal rods connected to the ends of said strip, and two bodies of insulating material molded around the joints between said rods and said strip and respectively fitting in the ends of said casin 3. in electric fuse, comprising a fuse strip, terminal rods connected to the ends thereof, two bodies of insulating material inclosing the joints between said rods and said strip, and shouldered at their facing ends, and an envelop. inclosing said strip and receiving said bodies and seated at its ends against said shoulders.

4. A fuse strip, terminal rods connected to the ends thereof, two bodies of insulatin material inclosing the joints between said rods and said strip, the said bpdies being shouldered at their'facing ends and convex at their outer ends, and a tubular envelop inclosing said strip and receiving said bodies and seated against said shoulders, the outer periphery of said envelop registering with the outer adjacent surfaces of said bodies.

5. An electric fuse, comprising. a tubular casing, plu s of insulating material closing the ends 0 "said casing and protruding beyond said ends, terminal rods entering said .plugs, and a fuse strip in said casing connect d to said rods; the saidrods extending partly through said plugs, whereby the joints between the ends of said fuse strip and said plugs become wholly inclosed in said insulating material.

In testimony whereof I have atli'xed my signature in presence of two witnesses:

THOMAS E. MURRAY. IWitnesses: 4

S GEBTRUDE TJPORTER,- MAI T. MoGA mY. 

